1. Field of the Invention
The present invention relates to a radiation imaging apparatus that acquires a radiation image from radiation transmitted through a subject.
2. Description of the Related Art
As a radiation imaging apparatus, there is widely used a digital X-ray imaging apparatus that uses digital radiography for instantaneously displaying a captured image on a monitor. Conventionally, the imaging apparatus of this type has been installed in a radiation room to be utilized. Recently, however, there is a big demand for a portable imaging apparatus (electronic cassette) to enable quick image-capturing operations throughout a medical facility.
Mainstream among such portable imaging apparatuses is a product having a handle for portability. However, the handle may be an obstacle for a certain imaging method. This requires the handle to be detachable.
Further, to enable image-capturing of a region such as a chest or an abdomen of a patient where many scattered rays maybe generated, there is a demand for a mechanism (grid holding unit) for holding a grid to remove the scattered rays. Thus, an X-ray imaging apparatus discussed in Japanese Patent Application Laid-Open No. 2005-6806 includes a case provided with a handle used for carrying, to which the electronic cassette and the grid can be detachably mounted.
In the X-ray imaging apparatus discussed in Japanese Patent Application Laid-Open No. 2005-6806, the three units, i.e., the electronic cassette, the handle, and the grid, can be combined. Operating the handle enables replacement of the grid from the combined state of the three units. The electronic cassette can also be taken out. However, the X-ray imaging apparatus discussed in Japanese Patent Application Laid-Open No. 2005-6806 additionally needs a grid holding unit to combine the electronic cassette and the grid by removing the handle.